Si microchannel cooler integrated with high power amplifiers for base station of mobile communication systems

This study demonstrated the first application of a Si microchannel cooler integrated with bump structures to apply as a new thermal management device for the high power amplifiers (HPAs). The structure consists of an HPA chip, Si bumps, and a Si microchannel cooler. The fine pitch Si bumps with metal coating are directly connected to the electrodes close to the active areas of AlGaN/GaN HEMT HPAs. The bump functions not only as a source electrode for small ground inductance, but also as the heat transfer path from HPAs. The heat from bumps is successfully transferred by the microchannel cooler. This first prototype of a Si microchannel cooler bonded to HPAs achieved a decrease of 0.3 °C/W in total thermal resistance compared to conventional face-up mounted HPAs.